Need help with credit card connection.

I have just connected my credit card, and yes this credit card is connected to another account as well, but it keeps saying contact support i have all the information correct so what am i doing wrong?

Edit: I have now reentered all the information to the exact same effect beggining to get frustrated with this... I have heard that itunes is having difiuclties today but i have been trying to do this for two days now so not really sure what to do??